Comparison of Cognitive Impairment between Patients having Epilepsy and Psychogenic Nonepileptic Seizures

Neurocognitive performance in functional neurological disorder: A systematic review and meta-analysis

BACKGROUND AND PURPOSE

Cognitive complaints are common in functional neurological disorder (FND), but it is unclear whether objective neurocognitive deficits are present. This systematic review summarized validated/standardized cognitive test performance in FND samples across cognitive domains.

METHODS

Embase, PsycInfo and MEDLINE were searched from inception to 15 May 2023, combining terms for FND and cognitive domains (e.g., attention, memory, executive functioning). Studies included a range of FND phenotypes (seizures, motor, cognitive disorder, mixed), compared to healthy or clinical controls. Risk of bias was assessed with the modified Newcastle-Ottawa Scale and a qualitative synthesis/narrative review of cognitive performance in FND was conducted. Test performance scores were extracted, and random effects meta-analyses were run where appropriate. This review was registered on PROSPERO, CRD42023423139.

RESULTS

Fifty-six studies including 2260 individuals with FND were eligible. Although evidence for some impairments emerged across domains of executive functioning, attention, memory and psychomotor/processing speed, this was inconsistent across studies and FND phenotypes. Common confounds included group differences in demographics, medication and intellectual functioning. Only 24% of studies objectively assessed performance validity. Meta-analyses revealed higher scores on tests of naming (g = 0.67, 95% confidence interval [CI] 0.50, 0.84) and long-term memory (g = 0.43, 95% CI 0.13, 0.74) in functional seizures versus epilepsy, but no significant differences in working (g = -0.08, 95% CI -0.44, 0.29) or immediate (g = 0.25, 95% CI -0.02, 0.53) memory and cognitive flexibility (g = -0.01, 95% CI -0.29, 0.28).

CONCLUSIONS

There is mixed evidence for objective cognitive deficits in FND. Future research should control for confounds, include tests of performance validity, and assess relationships between objective and subjective neurocognitive functioning.

Associations of cognitive test performance with self-reported mental health, cognition, and quality of life in adults with functional seizures: A systematic review and meta-analysis

Objective: People with functional seizures (FS) have frequent and disabling cognitive dysfunction and mental health symptoms, with low quality of life. However, interrelationships among these constructs are poorly understood. In this meta-analysis, we examined associations between objective (i.e. performance-based) cognitive testing and self-reported (i) mental health, (ii) cognition, and (iii) quality of life in FS. Method: We searched MEDLINE, Embase, PsycINFO, and Web of Science, with the final search on June 10, 2024. Inclusion criteria were studies documenting relationships between objective cognitive test scores and self-reported (i.e. subjective) mental health, cognition, and/or quality of life in adults with FS. Exclusion criteria were mixed FS/epilepsy samples. A modified Newcastle-Ottawa Scale evaluated risk of bias. This project is registered as CRD42023392385 in PROSPERO. Results: Initially, 4,054 unique reports were identified, with the final sample including 24 articles of 1,173 people with FS. Mean age was 35.9 (SD = 3.9), mean education was 12.6 (SD = 1.3), and proportion of women was 73.9%. Risk of bias was moderate, due in part to inconsistent reporting of confounding demographic variables. Significant relationships were found between global objective cognition and global self-reported mental health (k = 21, Z = -0.23 [0.04], 95% CI = -0.30, -0.16), depression (k = 11, Z = -0.13 [0.05], 95% CI = -0.21, -0.04), cognition (k = 5, Z = -0.16 [0.05], 95% CI = -0.26, -0.06), and quality of life (k = 5, Z = -0.17 [0.05], 95% CI = -0.24, -0.10). Exploratory analyses showed associations between select cognitive and mental health constructs. Conclusions: Objective cognition is reliably associated with self-reported mental health, cognition, and quality of life in people with FS. Scientific and clinical implications are discussed.

Cognitive correlates of psychopathology in functional/dissociative seizures and non-lesional epilepsy: An exploratory study

OBJECTIVE

To explore the relationship between cognitive functioning and psychopathological features in Functional/Dissociative Seizures (FDS), and test whether this differs from that observed in epilepsy.

METHODS

We recruited a cross-sectional sample of adults (age > 18) with a diagnosis of non-lesional epilepsy or FDS between January 2021 and July 2022 (n = 73). Participants completed a series of psychiatric questionnaires and neuropsychological measures. Spearman's Correlation Coefficient was computed between each of the psychiatric and cognitive measures in each group. Fisher's Z test of significance for independent correlation coefficients then tested the significance of the difference between correlation coefficients for the two groups.

RESULTS

There were no group differences in neuropsychological test scores. However, people with FDS reported higher seizure severity, depression levels, number of medically unexplained somatic symptoms, and exposure to traumatic events compared to epilepsy. Results of the Fisher's Z-test revealed significant differences in correlation coefficients between groups in two instances. First, in the association between the number of traumatic experiences and cognitive switching (z = 2.77, p = 0.006); the number of traumatic experiences were positively associated with cognitive switching in epilepsy but showed a non-significant negative trend in FDS. Secondly, in the association between vocabulary abilities and the number of medically unexplained symptoms (z = -2.71; p = 0.007); higher vocabulary ability was associated with fewer somatic symptoms in epilepsy, while no such correlation was observed in FDS.

SIGNIFICANCE

This study provides preliminary evidence for the complex interplay between cognitive functioning and psychopathology in FDS and epilepsy. Neurocognitive functioning such as vocabulary abilities or attentional switching may play a role in the expression or maintenance of pathological features of FDS.

Emotional intelligence in children with epilepsy

Objective

Epilepsy is a prevalent neurological disorder in the pediatric population, often accompanied by comorbidities, drug-related burdens, and psychosocial issues. Emotional intelligence (EI) is a crucial aspect of neurocognitive functioning that may be impaired in various clinical conditions. This study aimed to assess EI and its associated risk factors in children with epilepsy.

Methods

In a case-control design, we recruited 47 children with epilepsy (37 males, mean age 10.5 ± 3.1 years) and age- and gender-matched controls. Participants were evaluated using the Emotional Quotient Inventory: Youth Version (EQ-I:YV). We included risk factors, including comorbidities, perinatal complications, epilepsy characteristics, and magnetic resonance imaging results to predict EI.

Results

Results indicate that children with epilepsy demonstrated significantly lower EI scores compared to controls (Total EQ score: p = 0.031, intrapersonal: p < 0.001, adaptability: p = 0.03, and general mood: p < 0.001). Multiple linear regression analysis indicated that lower total EQ scores were associated with the number of anti-epileptic drugs, age, seizure frequency, MRI abnormalities, aura, and early onset of seizures.

Conclusions

The study provides evidence that children with epilepsy exhibit lower EQ scores than control group, with notable differences in intrapersonal skills, adaptability, and general mood. Additionally, age, and some seizure-related factors predicted decreased total EQ scores. These findings emphasize the need to consider EI in the context of pediatric epilepsy, as impaired EI may contribute to further psychosocial challenges faced by affected children.

AARS and CACNA1A mutations: diagnostic insights into a case report of uncommon epileptic encephalopathy phenotypes in two siblings

Epilepsy, characterized by recurrent seizures, impacts 70-80% of patients, leading to cognitive deficits. The intricate relationship between seizure control and cognitive impairment remains complex. Epileptic encephalopathy (EE), an intensified form often rooted in genetic factors, is detectable through next-generation sequencing, aiding in precise diagnoses, family counseling, and potential treatment strategies. We present a case involving two sisters with refractory generalized seizures evolving into dysarthria, dysphagia, ataxia, and cognitive decline. Despite normal physical exams, abnormal electroencephalogram results consistent with epilepsy were noted. Whole Exome Sequencing identified heterozygous variants in the alanyl-tRNA synthetase (AARS) and Calcium Voltage-Gated Channel Subunit Alpha 1 (CACNA1A) genes. The AARS variant (c.C2083T, p.R695*) was maternal, while the CACNA1A variant (c.G7400C, p.R2467P) was paternal. Patients A and B exhibited a unique blend of neurological and psychiatric conditions, distinct from common disorders that begin adolescence, like Juvenile Myoclonic Epilepsy. Whole Exome Sequencing uncovered an AARS gene and CACNA1A gene, linked to various autosomal dominant phenotypes. Presence in both parents, coupled with familial reports of migraines and seizures, provides insight into accelerated symptom progression. This study underscores the importance of genetic testing in decoding complex phenotypes and emphasizes the value of documenting family history for anticipating related symptoms and future health risks.

Semantic verbal fluency in native speakers of Turkish: a systematic review of category use, scoring metrics and normative data in healthy individuals

INTRODUCTION

Semantic verbal fluency (SVF) is a widely used measure of frontal executive function and access to semantic memory. SVF scoring metrics include the number of unique words generated, perseverations, intrusions, semantic cluster size and switching between clusters, and scores vary depending on the language the test is administered in. In this paper, we review the existing normative data for Turkish, the main metrics used for scoring SVF data in Turkish, and the most frequently used categories.

METHOD

We conducted a systematic review of peer-reviewed papers using Medline, EMBASE, PsycInfo, Web of Science, and two Turkish databases, TR-Dizin and Yok-Tez. Included papers contained data on the SVF performance of healthy adult native speakers of Turkish, and reported the categories used. Versions of the SVF that required participants to alternate categories were excluded. We extracted and tabulated demographics, descriptions of groups, metrics used, categories used, and sources of normative data. Studies were assessed for level of detail in reporting findings.

RESULTS

1400 studies were retrieved. After deduplication, abstract, full text screening, and merging of theses with their published versions, 121 studies were included. 114 studies used the semantic category "animal", followed by first names (N = 14, 12%). All studies reported word count. More complex measures were rare (perseverations: N = 12, 10%, clustering and switching: N = 5, 4%). Four of seven normative studies reported only word count, two also measured perseverations, and one reported category violations and perseverations. Two normative studies were published in English.

CONCLUSIONS

There is a lack of normative Turkish SVF data with more complex metrics, such as clustering and switching, and a lack of normative data published in English. Given the size of the Turkish diaspora, normative SVF data should include monolingual and bilingual speakers. Limitations include a restriction to key English and Turkish databases.

Objective and subjective neurocognitive functioning in functional motor symptoms and functional seizures: preliminary findings

INTRODUCTION

This study aimed to provide a preliminary assessment of objective and subjective neurocognitive functioning in individuals with functional motor symptoms (FMS) and/or functional seizures (FS). We tested the hypotheses that the FMS/FS group would display poorer objective attentional and executive functioning, altered social cognition, and reduced metacognitive accuracy.

METHOD

Individuals with FMS/FS (n = 16) and healthy controls (HCs, n = 17) completed an abbreviated CANTAB battery, and measures of intellectual functioning, subjective cognitive complaints, performance validity, and comorbid symptoms. Subjective performance ratings were obtained to assess local metacognitive accuracy.

RESULTS

The groups were comparable in age (p = 0.45), sex (p = 0.62), IQ (p = 0.57), and performance validity (p-values = 0.10-0.91). We observed no impairment on any CANTAB test in this FMS/FS sample compared to HCs, although the FMS/FS group displayed shorter reaction times on the Emotional Bias task (anger) (p = 0.01, np2 = 0.20). The groups did not differ in subjective performance ratings (p-values 0.15). Whilst CANTAB attentional set-shifting performance (total trials/errors) correlated with subjective performance ratings in HCs (p-values<0.005, rs = -0.85), these correlations were non-significant in the FMS/FS sample (p-values = 0.10-0.13, rs-values = -0.46-0.50). The FMS/FS group reported more daily cognitive complaints than HCs (p = 0.006, g = 0.92), which were associated with subjective performance ratings on CANTAB sustained attention (p = 0.001, rs = -0.74) and working memory tests (p < 0.001, rs = -0.75), and with depression (p = 0.003, rs = 0.70), and somatoform (p = 0.003, rs = 0.70) and psychological dissociation (p-values<0.005, rs-values = 0.67-0.85).

CONCLUSIONS

These results suggest a discordance between objective and subjective neurocognitive functioning in this FMS/FS sample, reflecting intact test performance alongside poorer subjective cognitive functioning. Further investigation of neurocognitive functioning in FND subgroups is necessary.

Cognitive functions and epilepsy-related characteristics in patients with generalized tonic–clonic epilepsy: a cross-sectional study

Background

Epilepsy is a brain disorder affecting nearly 65 million people worldwide. It is characterized by sudden, transient, and uncontrolled episodes of brain dysfunction secondary to hypersynchronous abnormal discharge of cortical neuronal cells resulting in motor, sensory, and behavioral manifestations. Cognitive deterioration can occur in approximately 70–80% of epileptic patients with a variety of epilepsy-related characteristics being implicated. This study aimed to assess cognitive functions in a sample of patients with generalized tonic–clonic epilepsy and determine its relation to different epilepsy-related characteristics. It was designed as a case–control cross-sectional study in which 106 participants were enrolled and divided into two groups: a case group of fifty-three patients diagnosed with generalized tonic–clonic epilepsy and a control group including fifty-three healthy subjects. Sociodemographic and epilepsy-related characteristics and a variety of cognitive functions were assessed for both groups.

Results

Epileptic patients were significantly suffering from impairment in attention, memory, visuospatial (P = 0.001), and language functions (P = 0.018) compared to the healthy control group.

Conclusions

Epileptic patients are significantly suffering from cognitive impairment with a variety of contributing epilepsy-related characteristics.

Neuropsychological performance and effort in patients diagnosed with psychogenic nonepileptic seizures - Descriptive study of a Czech sample

PURPOSE

The aim of the study was to examine the neuropsychological performance and effort in patients with a confirmed PNES diagnosis. The second aim of the study was to investigate the relationship between validity indicators from the cognitive battery with validity and clinical scales from a personality scale.

METHOD

Patients with PNES (N = 250; F:M 186:64; mean age 38.32 (13.23)) were assessed utilizing the RBANS (Czech Research version) to evaluate cognitive performance and to obtain the Effort Index. The MMPI-2 was used to evaluate personality and psychopathology.

RESULTS

Global cognitive performance was 0.92 SD below average (according to the Gaussian distribution) in patients with PNES. The lowest scores in the sample were in the Attention domain (-1.7SD). Insufficient effort was detected in 10% of patients. Education correlated negatively with the Effort index (rs = -0.25, p = 0.01). A mild significant correlation in Scale 7 (rs = 0.21, p = 0.01) and Scale 8 (rs = 0.24, p = 0.01), and a significant correlation between Effort Index and Back F Scale (rs = 0.23, p = 0.01) were noted.

CONCLUSIONS

Assessment of cognitive performance and effort is an essential part of the comprehensive evaluation of patients with PNES during their hospitalization at Epilepsy centers. Many aspects of the neuropsychological assessment can offer useful indications for reaching a differential diagnosis, including clinical history, behavioral observations, cognitive and symptom validity testing, and structured psychological inventories.

Cognitive Impairment in People with Epilepsy

People with epilepsy frequently have cognitive impairment. The majority of cognitive problems is influenced by a variety of interlinked factors, including the early onset of epilepsy and the frequency, intensity and duration of seizures, along with the anti-epileptic drug treatment. With a systematic review, we investigate significant factors about the cognitive impairment in epilepsy. Most cognitive problems in adult people with epilepsy include memory, attention and executive function deficits. However, which cognitive area is mainly affected highly depends on the location of epileptic activity. Moreover, modifications in signalling pathways and neuronal networks have an essential role in both the pathophysiology of epilepsy and in the mechanism responsible for cognitive impairment. Additionally, studies have shown that the use of polytherapy in the treatment of epilepsy with anti-epileptic drugs (AEDs) heightens the risk for cognitive impairment. It can be challenging to distinguish the contribution of each factor, because they are often closely intertwined.

The Comparison Between Neuropsychological Features of Psychogenic Non-epileptic Seizures and Epileptic Seizures

Background: Both epileptic seizures (ES) and psychogenic non-epileptic seizures (PNES) are often associated with some degree of cognitive impairment. Video electroencephalography (EEG) monitoring is the gold standard for diagnosing PNES. This diagnostic procedure is costly and available in specific tertiary centers. Neuropsychological assessment can provide clues for the differential diagnosis of PNES and ES and help clarify the nature and etiology of these two disorders. Objectives: Therefore, this study aimed to compare the neuropsychological profiles of PNES and ES patients. Methods: In this analytical cross-sectional study, 30 patients with ES and 31 patients with PNES were compared by neuropsychiatric tests, such as the Wechsler Adult Intelligence scale (WAIS), Addenbrooke’s Cognitive examination (ACE), and California Verbal Learning test (CVLT). Results: There was a female predominance in the PNES group (female-to-male ratio = 4.16/1, P = 0.003). In the PNES group, 77.4% of the patients had a psychiatric disorder versus 66.7% of the patients in the ES group; however, the difference was not statistically significant (P = 0.34). The mean score of total intelligence was higher in the PNES group (84.77 ± 16.94), compared to the ES group (83.63 ± 10.04); however, the difference was not significant (P = 0.75). Based on the mean subscale scores, the digit symbol score (WAIS-IV subscale) and memory score (ACE subscale) were significantly higher in the PNES group compared to the ES group (P = 0.037 and 0.032, respectively). Conclusions: This study showed that neuropsychological assessments might not differentiate ES from non-epileptic seizures.

Psychogenic nonepileptic seizures: The effect of accurate diagnosis on cognition

OBJECTIVE

Much remains to be elucidated about the cognitive profile of patients with psychogenic nonepileptic seizures (PNES) and about how this changes over time and compares to that of patients with epilepsy. The aim of this study was to study the neuropsychological profile of patients with PNES and an age-matched group of patients with temporal lobe epilepsy (TLE) during admission to a video electroencephalography monitoring unit (VEMU) and 1 year after discharge.

METHODS

Patients diagnosed with PNES or TLE at a VEMU were prospectively recruited. Neuropsychological, demographic, clinical, and treatment variables were collected at baseline and 1 year. To minimize multiple comparisons, scores from different cognitive tests were computed for attention and psychomotor speed, verbal memory, visual memory, language, and executive function. A global cognitive impairment index (GCII) was also created. Post hoc analyses were conducted to identify clinical variables that might mediate the differences observed in cognition over time between the groups. These included seizure frequency, number of antiseizure medication (ASM), number of psychotropic drugs, depression, and quality of life.

RESULTS

We studied 24 patients with PNES and 24 patients with TLE. The groups performed similarly in the baseline neuropsychological tests. There was a significant time (baseline to 1-year follow-up) by group (PNES vs TLE) interaction for the GCII (p = 0.006), language (p = 0.04), and executive function (p = 0.013), with PNES patients showing improvement and TLE patients remaining stable. The time by group interaction for attention and psychomotor speed showed a trend toward significance (p = 0.056), Reduction in number of ASM was associated with improved cognition in PNES patients at 1 year.

CONCLUSION

PNES patients showed improved cognition at 1 year of follow-up, particularly in language and executive functions. This finding shows the potential benefits of an early, accurate diagnosis, which range from improved cognition to better management.

Social aspects of life in patients with functional seizures: Closing the gap in the biopsychosocial formulation

The human, as a biological system, is an open system embedded within larger systems -including the family, culture, and socio-political environment. In this context, a patient with functional seizures (FS) is embedded in relationships, educational/professional institutions, culture, and society. Both connection to these broader systems and the quality of these connections, as well as the soundness of each system in and of itself, influence the health and well-being of patients in positive or negative ways. The social aspects of life are important determinants of health and quality of life across the lifespan. The current narrative review brings out several overarching themes in patients with FS. Sections on attachment, marriage, social networking, and stigma highlight the central roles of supportive and affirmative relationships across the lifespan. The section on education underscores the importance of keeping children and youth with FS connected within their school environments, as well as managing any barriers - learning difficulties, school response to FS events, stigma, etc.-that can diminish this connection. Finally, the sections on employment and driving highlight the value of being an active participant in one's society. In summary, FS impacts patients across most social aspects of life domains regardless of age - factors that are important when developing biopsychosocial formulations. This review concludes that the multidisciplinary management of FS requires careful assessment of social aspects of life in patients which can then be targeted for treatment, to improve their quality of life, facilitating recovery, and reducing the risk of relapse.

Cognitive profiles in patients with epileptic and nonepileptic seizures evaluated using a brief cognitive assessment tool

BACKGROUND

There is a need for the development of brief tools to screen for cognitive impairments in epilepsy patients in order to prioritize and direct formal comprehensive cognitive testing. Yet, shorter cognitive screening tools are limited in their breadth of cognitive domains or have not been intensively studied on an epilepsy population. This study used a brief cognitive screening tool in order to compare cognitive profiles between patients with epilepsy and those with nonepileptic seizures.

METHODS

Patients admitted to the Royal Melbourne Hospital video-EEG monitoring unit between 2005 and 2017 were included. Patients were categorized according to seizure etiology (epileptic, psychogenic or other nonepileptic seizures), epilepsy syndrome (focal or generalized; temporal lobe (TLE) or extra-temporal lobe epilepsy (ETLE)), seizure frequency, and anti-seizure medications (ASMs). Attention, visuoconstructional, memory, executive, and language functioning were assessed with the Neuropsychiatry Unit Cognitive Assessment Tool (NUCOG). General linear mixed models were computed to investigate cognitive profiles according to diagnostic group and other clinicodemographic variables.

RESULTS

800 patients were included in the analysis (61% female and 39 % male, median age 36 years). Patients with both epileptic seizures and psychogenic seizures (n = 25) had the lowest total scores on NUCOG, followed by patients with epileptic seizures (n = 411), psychogenic seizures (n = 185), and nonepileptic seizures (n = 179, p = 0.002). Specifically, patients with epileptic seizures performed worse than those with nonepileptic seizures in the executive, language, and memory domain, and had lower language domain scores than those with psychogenic seizures. Patients with bilateral TLE had poorer performance than those with unilateral TLE, particularly for memory function. Specific ASMs and polypharmacy but not seizure frequency had a negative effect on cognition (p < 0.001). NUCOG scores did not differ between focal and generalized epilepsies, or between TLE and ETLE.

CONCLUSION

The NUCOG differentiated cognitive profiles in patients with uncontrolled seizures due to different etiologies. Bilateral TLE and medication adversely affected cognitive performance, and overall patients with epilepsy performed worse than those with nonepileptic seizures. These results provide further evidence for sensitivity of the NUCOG for detecting cognitive impairment in patients with seizure disorders.